Finish an old concrete slab?

[JosephNY]

Is the charcoal stain a serious recommendation? If so, can you please point me to some pictures?

And I'd really appreciate understanding why the slab is a POS (I have no emotional investment in whether it's a POS or the best slab ever; but I do want a nice floor).

Thanks!

 

[havasu]

If the concrete grinder is still working, now is the time to begin testing various stains. If you don't like the colors, the grinder could make a quick pass and erase the colors.

 

[Floorist]

I can't see that slab stained either.

 

[JosephNY]

I can't see that slab stained either.

Do you think I should leave it unstained?

There are certain areas where the mastic has slightly stained the concrete.

Thanks!

 

[Incognito]

Do you think I should leave it unstained?

There are certain areas where the mastic has slightly stained the concrete.

Thanks!

I think the guy on site doing all that work is your best resource at this point. I can tell he's reasonably experienced and certainly well equipped. So far he's done all you could ask of him. Your job appears to be falling into a "worst case scenario" kind of deal from what we can see.

One of the installers here mentioned a charcoal stain. I originally mentioned going with a darker, distressed look, or something to that effect if the slab isn't remotely new and clean looking as you grind down. Another excellent piece of advice given here was the Ardex colored/decorative topping products. I was trained to do those kinds of jobs but never actually did any. It's a great product and everything you've done so far would be normal "prep" necessary to clean the slab and get it ready for the topping materials.

I think you said the guy grinding said this is one of the worst slabs he's come up against. We're all in that boat at one time or another. I hope you appreciate all he's been through. It looks like a Goddamn nightmare.

But don't get discouraged. It'll all work out and it's only a floor, right?

 

[Ernesto]

Is the charcoal stain a serious recommendation? If so, can you please point me to some pictures?

And I'd really appreciate understanding why the slab is a POS (I have no emotional investment in whether it's a POS or the best slab ever; but I do want a nice floor).

Thanks!

The reason I said that is the cracks and surface structure is not coming out flat like a terrazo like surface. The concrete looks to soft and is rough, like it is crumbling a bit from the pictures you provided. Not going to look pretty.

Is this an on grade slab or a lightweight concrete poured in a pan upstairs?

 

[JosephNY]

The slab is 7" thick and was poured in 1960 and is about 160' above ground (apt building).

The installer polished a small area and put a dark stain on part of it, so we could see what it looks like.

Here it is:

 

[Floorist]

Looks okay if you can handle concrete floors. Too hard for people like me with back and feet problems.

 

[havasu]

I've seen a red stain on concrete and really liked it.